The present invention relates to an embroidery machine. More particularly, the present invention relates to an embroidery machine and method for transferring an embroidery frame contained in the embroidery machine backward when a thread is broken at an embroidery operation.
Generally, an embroidery machine embroiders an embroidery design on a fabric fixed on an embroidery frame during a needle holder contained in a sewing device moves up and down, and simultaneously, the embroidery frame moves to X-axis and Y-axis directions. Because the embroidery machine embroiders the embroidery design on the fabric while the embroidery frame moves to the X-axis and Y-axis directions, an accurate movement and a low vibration of the embroidery frame are closely involved with the quality of embroidery.
Conventionally, the embroidery machine includes an alternating current (AC) servomotor or an induction motor for moving the needle holder up and down. Further, the embroidery machine includes a stepping motor for moving the embroidery frame to the X-axis and Y-axis directions. Twelve to twenty-five sewing machines are serially connected in the form of one shaft so as to improve the productivity of the embroidery machine. Because the embroidery machine embroiders the embroidery design on the fabric with threads of different colors, each sewing device has six to twelve needle holders and needles contained in each needle holder are threaded with the threads of the different colors.
Recently, a convenient input, copy, save, and edition of an embroidery design data is needed in the embroidery machine. Also a user prefers an automatic embroidery machine. The automatic embroidery machine has an automatic thread changing function according to the embroidery design. After the embroidery operation has been completed, the automatic embroidery machine has a function capable of cutting a thread. When the thread is broken at the embroidery operation, the automatic embroidery machine has a function capable of stopping the automatic embroidery machine and displaying an alarm indication. When the automatic embroidery machine is stopped due to an abnormal power-off, the automatic embroidery machine has a function capable of recovering a power supply. Furthermore, a manufacturer or a merchandiser wants to use the embroidery machine including a computer or a microprocessor for implementing the embroidery machine having multiple functions.
Referring to FIG. 1, there is shown a block diagram illustrating a conventional embroidery machine. As shown, the conventional embroidery machine includes a function selection panel 10, an embroidery frame driver 20, a thread breakage detector 30, and a control unit 40. The function selection panel 10 has function selection keys for selecting a plurality of functions. The embroidery-frame driver 20 drives the embroidery frame in response to a control signal outputted from the control unit 40. The thread breakage detector 30 detects a broken thread. The control unit 40 controls the embroidery machine with a memory storing a program necessary to control the embroidery machine. If the thread breakage detector 30 detects the broken thread, the control unit 40 stops the embroidery operation. In addition, the control unit 40 is coupled to a setting data storage 50 and an embroidery design storage 60. The setting data storage 50 and the embroidery design storage 60 can be located in the inside or outside of the control unit 40. The setting data storage 50 stores a plurality of setting data needed for the embroidery operation, wherein the setting data includes an embroidery operation speed, selected needle holder-related information, etc. The embroidery design storage 60 stores embroidery design information. The control unit 40 can be implemented as a microprocessor. When the user selects a desired embroidery design from embroidery designs stored in the embroidery design storage 60, the control unit 40 controls the embroidery-frame driver 20.
When the thread is broken at the embroidery operation, the thread breakage detector 30 detects the broken thread and transmits a detection signal to the control unit 40. The control unit 40 can include a display, a lamp or a buzzer not shown in FIG. 1. When the thread is broken, the control unit 40 alarms the user through the display unit, the lamp or the buzzer. At this time, the control unit 40 controls the embroidery-frame driver 20 to stop the operation of the embroidery frame. Further, the user recognizes the broken thread through the display, the lamp or the buzzer. Then, the user finds out a needle of the broken thread and re-threads the needle of the broken thread.
At a state that the embroidery frame contained in the conventional embroidery machine is moved forward, the user should re-thread the needle of the broken thread. When the user re-threads the needle of the broken thread, the embroidery frame moved forward can be obstruction. Accordingly, the user employs a footstool to reach the needle of the broken thread. However, in case that the length of the embroidery machine is more than 750 mm, the user cannot easily re-thread the needle of the broken thread.
It is, therefore, an object of the present invention to provide an embroidery machine and method capable of transferring an embroidery frame backward so that a user can easily re-thread a needle of a broken thread in case of thread breakage.
It is, therefore, another object of the present invention to provide an embroidery machine and method capable of transferring an embroidery frame backward when a thread, especially, an upper-positioned thread is broken.
It is, therefore, further another object of the present invention to provide an embroidery machine and method capable of selectively setting an embroidery-frame transfer distance.
It is, therefore, still further another object of the present invention to provide an embroidery machine including an embroidery frame, which can be transferred backward or forward in response to a user request.
In accordance with a first aspect of the present invention, there is provided an embroidery machine for transferring an embroidery frame backward in case of thread breakage, the embroidery machine including the embroidery frame and needle holders holding needles, comprising: detection means for detecting the thread breakage to generate a thread breakage signal if the thread breakage occurs at a needle contained in the needle holders; transfer means for transferring the embroidery frame backward in response to a control signal; and control means, coupled to said detection means and said transfer means, for generating the control signal to control said transfer means in response to the thread breakage signal.
In accordance with a second aspect of the present invention, there is provided an embroidery machine for transferring an embroidery frame backward in case of thread breakage, the embroidery machine including the embroidery frame and needle holders holding needles, comprising: generation means for generating an embroidery-frame transfer request signal in response to a user request if the thread breakage occurs at a needle contained in the needle holders; transfer means for transferring the embroidery frame backward in response to a control signal; and control means, coupled to said transfer means and said generation means, for generating the control signal to control said transfer means in response to the embroidery-frame transfer request signal.
In accordance with a third aspect of the present invention, there is provided a method for transferring an embroidery frame backward in case of thread breakage, comprising the steps of: a) detecting the thread breakage to generate a thread breakage signal if the thread breakage occurs at a needle contained in needle holders; b) generating the control signal to control an embroidery-frame driver in response to the thread breakage signal; and c) transferring the embroidery frame backward in response to the control signal.
In accordance with a fourth aspect of the present invention, there is provided a method for transferring an embroidery frame backward in case of thread breakage, comprising the steps of: a) generating an embroidery-frame transfer request signal in response to a user request if the thread breakage occurs at a needle contained in needle holders; b) generating a control signal to control an embroidery-frame driver in response to the embroidery-frame transfer request signal; and c) transferring the embroidery frame backward in response to the control signal.